...335d has torque, space and fuel economy over 135i, 135i has everything else over 335d.

I would add that the 3-series has more "goodies" available (or were likely ordered with more): park distance, auto-dimming mirrors, etc. Many of the 1-series are more spartanly-equipped.

The 335d does a 1/4 mile in about 14.2s, 135i probably mid-13s or so. Part of the reason is the different gearing and changes - 335d has to shift before 60mph, 135i runs up to 70 or so. There's also the weight - the 335d sedan weighs at least a couple hundred lbs more than the smaller 1-series coupe.

But to tell you how fast a 335d is: if you are doing 50 and need to pass 2 cars or a semi, and floor it, you will be doing 90+ when you pull back in. The diesel is arguably better for those type of maneuvers, as HP doesn't come into play much in that scenario.

HP definitely comes into play at higher speeds, because HP is what combats wind resistance. It's also what helps you climb hills. The more HP you have, the more power you can expend per unit of time. Torque is how strong a push you get initially.